/*
 * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

/*
 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  * Neither the name of JSR-310 nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package java.time.chrono;

import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.ERA;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
import static java.time.temporal.ChronoField.YEAR_OF_ERA;

import java.io.Serializable;
import java.time.DateTimeException;
import java.time.temporal.ChronoUnit;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAmount;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalUnit;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;
import java.util.Objects;

/**
 * A date expressed in terms of a standard year-month-day calendar system. <p> This class is used by
 * applications seeking to handle dates in non-ISO calendar systems. For example, the Japanese,
 * Minguo, Thai Buddhist and others. <p> {@code ChronoLocalDate} is built on the generic concepts of
 * year, month and day. The calendar system, represented by a {@link java.time.chrono.Chronology},
 * expresses the relationship between the fields and this class allows the resulting date to be
 * manipulated. <p> Note that not all calendar systems are suitable for use with this class. For
 * example, the Mayan calendar uses a system that bears no relation to years, months and days. <p>
 * The API design encourages the use of {@code LocalDate} for the majority of the application. This
 * includes code to read and write from a persistent data store, such as a database, and to send
 * dates and times across a network. The {@code ChronoLocalDate} instance is then used at the user
 * interface level to deal with localized input/output.
 *
 * <P>Example: </p>
 * <pre>
 *        System.out.printf("Example()%n");
 *        // Enumerate the list of available calendars and print today for each
 *        Set&lt;Chronology&gt; chronos = Chronology.getAvailableChronologies();
 *        for (Chronology chrono : chronos) {
 *            ChronoLocalDate date = chrono.dateNow();
 *            System.out.printf("   %20s: %s%n", chrono.getID(), date.toString());
 *        }
 *
 *        // Print the Hijrah date and calendar
 *        ChronoLocalDate date = Chronology.of("Hijrah").dateNow();
 *        int day = date.get(ChronoField.DAY_OF_MONTH);
 *        int dow = date.get(ChronoField.DAY_OF_WEEK);
 *        int month = date.get(ChronoField.MONTH_OF_YEAR);
 *        int year = date.get(ChronoField.YEAR);
 *        System.out.printf("  Today is %s %s %d-%s-%d%n", date.getChronology().getID(),
 *                dow, day, month, year);
 *
 *        // Print today's date and the last day of the year
 *        ChronoLocalDate now1 = Chronology.of("Hijrah").dateNow();
 *        ChronoLocalDate first = now1.with(ChronoField.DAY_OF_MONTH, 1)
 *                .with(ChronoField.MONTH_OF_YEAR, 1);
 *        ChronoLocalDate last = first.plus(1, ChronoUnit.YEARS)
 *                .minus(1, ChronoUnit.DAYS);
 *        System.out.printf("  Today is %s: start: %s; end: %s%n", last.getChronology().getID(),
 *                first, last);
 * </pre>
 *
 * <h3>Adding Calendars</h3> <p> The set of calendars is extensible by defining a subclass of {@link
 * ChronoLocalDate} to represent a date instance and an implementation of {@code Chronology} to be
 * the factory for the ChronoLocalDate subclass. </p> <p> To permit the discovery of the additional
 * calendar types the implementation of {@code Chronology} must be registered as a Service
 * implementing the {@code Chronology} interface in the {@code META-INF/Services} file as per the
 * specification of {@link java.util.ServiceLoader}. The subclass must function according to the
 * {@code Chronology} class description and must provide its {@link java.time.chrono.Chronology#getId()
 * chronlogy ID} and {@link Chronology#getCalendarType() calendar type}. </p>
 *
 * @param <D> the ChronoLocalDate of this date-time
 * @implSpec This abstract class must be implemented with care to ensure other classes operate
 * correctly. All implementations that can be instantiated must be final, immutable and thread-safe.
 * Subclasses should be Serializable wherever possible.
 * @since 1.8
 */
abstract class ChronoLocalDateImpl<D extends ChronoLocalDate>
    implements ChronoLocalDate, Temporal, TemporalAdjuster, Serializable {

  /**
   * Serialization version.
   */
  private static final long serialVersionUID = 6282433883239719096L;

  /**
   * Casts the {@code Temporal} to {@code ChronoLocalDate} ensuring it bas the specified chronology.
   *
   * @param chrono the chronology to check for, not null
   * @param temporal a date-time to cast, not null
   * @return the date-time checked and cast to {@code ChronoLocalDate}, not null
   * @throws ClassCastException if the date-time cannot be cast to ChronoLocalDate or the chronology
   * is not equal this Chronology
   */
  static <D extends ChronoLocalDate> D ensureValid(Chronology chrono, Temporal temporal) {
    @SuppressWarnings("unchecked")
    D other = (D) temporal;
    if (chrono.equals(other.getChronology()) == false) {
      throw new ClassCastException(
          "Chronology mismatch, expected: " + chrono.getId() + ", actual: " + other.getChronology()
              .getId());
    }
    return other;
  }

  //-----------------------------------------------------------------------

  /**
   * Creates an instance.
   */
  ChronoLocalDateImpl() {
  }

  @Override
  @SuppressWarnings("unchecked")
  public D with(TemporalAdjuster adjuster) {
    return (D) ChronoLocalDate.super.with(adjuster);
  }

  @Override
  @SuppressWarnings("unchecked")
  public D with(TemporalField field, long value) {
    return (D) ChronoLocalDate.super.with(field, value);
  }

  //-----------------------------------------------------------------------
  @Override
  @SuppressWarnings("unchecked")
  public D plus(TemporalAmount amount) {
    return (D) ChronoLocalDate.super.plus(amount);
  }

  //-----------------------------------------------------------------------
  @Override
  @SuppressWarnings("unchecked")
  public D plus(long amountToAdd, TemporalUnit unit) {
    if (unit instanceof ChronoUnit) {
      ChronoUnit f = (ChronoUnit) unit;
      switch (f) {
        case DAYS:
          return plusDays(amountToAdd);
        case WEEKS:
          return plusDays(Math.multiplyExact(amountToAdd, 7));
        case MONTHS:
          return plusMonths(amountToAdd);
        case YEARS:
          return plusYears(amountToAdd);
        case DECADES:
          return plusYears(Math.multiplyExact(amountToAdd, 10));
        case CENTURIES:
          return plusYears(Math.multiplyExact(amountToAdd, 100));
        case MILLENNIA:
          return plusYears(Math.multiplyExact(amountToAdd, 1000));
        case ERAS:
          return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
      }
      throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
    }
    return (D) ChronoLocalDate.super.plus(amountToAdd, unit);
  }

  @Override
  @SuppressWarnings("unchecked")
  public D minus(TemporalAmount amount) {
    return (D) ChronoLocalDate.super.minus(amount);
  }

  @Override
  @SuppressWarnings("unchecked")
  public D minus(long amountToSubtract, TemporalUnit unit) {
    return (D) ChronoLocalDate.super.minus(amountToSubtract, unit);
  }

  //-----------------------------------------------------------------------

  /**
   * Returns a copy of this date with the specified number of years added.
   * <p>
   * This adds the specified period in years to the date.
   * In some cases, adding years can cause the resulting date to become invalid.
   * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure
   * that the result is valid. Typically this will select the last valid day of the month.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param yearsToAdd the years to add, may be negative
   * @return a date based on this one with the years added, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  abstract D plusYears(long yearsToAdd);

  /**
   * Returns a copy of this date with the specified number of months added.
   * <p>
   * This adds the specified period in months to the date.
   * In some cases, adding months can cause the resulting date to become invalid.
   * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure
   * that the result is valid. Typically this will select the last valid day of the month.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param monthsToAdd the months to add, may be negative
   * @return a date based on this one with the months added, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  abstract D plusMonths(long monthsToAdd);

  /**
   * Returns a copy of this date with the specified number of weeks added.
   * <p>
   * This adds the specified period in weeks to the date.
   * In some cases, adding weeks can cause the resulting date to become invalid.
   * If this occurs, then other fields will be adjusted to ensure that the result is valid.
   * <p>
   * The default implementation uses {@link #plusDays(long)} using a 7 day week.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param weeksToAdd the weeks to add, may be negative
   * @return a date based on this one with the weeks added, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  D plusWeeks(long weeksToAdd) {
    return plusDays(Math.multiplyExact(weeksToAdd, 7));
  }

  /**
   * Returns a copy of this date with the specified number of days added.
   * <p>
   * This adds the specified period in days to the date.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param daysToAdd the days to add, may be negative
   * @return a date based on this one with the days added, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  abstract D plusDays(long daysToAdd);

  //-----------------------------------------------------------------------

  /**
   * Returns a copy of this date with the specified number of years subtracted.
   * <p>
   * This subtracts the specified period in years to the date.
   * In some cases, subtracting years can cause the resulting date to become invalid.
   * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure
   * that the result is valid. Typically this will select the last valid day of the month.
   * <p>
   * The default implementation uses {@link #plusYears(long)}.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param yearsToSubtract the years to subtract, may be negative
   * @return a date based on this one with the years subtracted, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  @SuppressWarnings("unchecked")
  D minusYears(long yearsToSubtract) {
    return (yearsToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl<D>) plusYears(Long.MAX_VALUE))
        .plusYears(1) : plusYears(-yearsToSubtract));
  }

  /**
   * Returns a copy of this date with the specified number of months subtracted.
   * <p>
   * This subtracts the specified period in months to the date.
   * In some cases, subtracting months can cause the resulting date to become invalid.
   * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure
   * that the result is valid. Typically this will select the last valid day of the month.
   * <p>
   * The default implementation uses {@link #plusMonths(long)}.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param monthsToSubtract the months to subtract, may be negative
   * @return a date based on this one with the months subtracted, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  @SuppressWarnings("unchecked")
  D minusMonths(long monthsToSubtract) {
    return (monthsToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl<D>) plusMonths(
        Long.MAX_VALUE)).plusMonths(1) : plusMonths(-monthsToSubtract));
  }

  /**
   * Returns a copy of this date with the specified number of weeks subtracted.
   * <p>
   * This subtracts the specified period in weeks to the date.
   * In some cases, subtracting weeks can cause the resulting date to become invalid.
   * If this occurs, then other fields will be adjusted to ensure that the result is valid.
   * <p>
   * The default implementation uses {@link #plusWeeks(long)}.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param weeksToSubtract the weeks to subtract, may be negative
   * @return a date based on this one with the weeks subtracted, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  @SuppressWarnings("unchecked")
  D minusWeeks(long weeksToSubtract) {
    return (weeksToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl<D>) plusWeeks(Long.MAX_VALUE))
        .plusWeeks(1) : plusWeeks(-weeksToSubtract));
  }

  /**
   * Returns a copy of this date with the specified number of days subtracted.
   * <p>
   * This subtracts the specified period in days to the date.
   * <p>
   * The default implementation uses {@link #plusDays(long)}.
   * <p>
   * This instance is immutable and unaffected by this method call.
   *
   * @param daysToSubtract the days to subtract, may be negative
   * @return a date based on this one with the days subtracted, not null
   * @throws DateTimeException if the result exceeds the supported date range
   */
  @SuppressWarnings("unchecked")
  D minusDays(long daysToSubtract) {
    return (daysToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl<D>) plusDays(Long.MAX_VALUE))
        .plusDays(1) : plusDays(-daysToSubtract));
  }

  //-----------------------------------------------------------------------
  @Override
  public long until(Temporal endExclusive, TemporalUnit unit) {
    Objects.requireNonNull(endExclusive, "endExclusive");
    ChronoLocalDate end = getChronology().date(endExclusive);
    if (unit instanceof ChronoUnit) {
      switch ((ChronoUnit) unit) {
        case DAYS:
          return daysUntil(end);
        case WEEKS:
          return daysUntil(end) / 7;
        case MONTHS:
          return monthsUntil(end);
        case YEARS:
          return monthsUntil(end) / 12;
        case DECADES:
          return monthsUntil(end) / 120;
        case CENTURIES:
          return monthsUntil(end) / 1200;
        case MILLENNIA:
          return monthsUntil(end) / 12000;
        case ERAS:
          return end.getLong(ERA) - getLong(ERA);
      }
      throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
    }
    Objects.requireNonNull(unit, "unit");
    return unit.between(this, end);
  }

  private long daysUntil(ChronoLocalDate end) {
    return end.toEpochDay() - toEpochDay();  // no overflow
  }

  private long monthsUntil(ChronoLocalDate end) {
    ValueRange range = getChronology().range(MONTH_OF_YEAR);
    if (range.getMaximum() != 12) {
      throw new IllegalStateException(
          "ChronoLocalDateImpl only supports Chronologies with 12 months per year");
    }
    long packed1 = getLong(PROLEPTIC_MONTH) * 32L + get(DAY_OF_MONTH);  // no overflow
    long packed2 = end.getLong(PROLEPTIC_MONTH) * 32L + end.get(DAY_OF_MONTH);  // no overflow
    return (packed2 - packed1) / 32;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj instanceof ChronoLocalDate) {
      return compareTo((ChronoLocalDate) obj) == 0;
    }
    return false;
  }

  @Override
  public int hashCode() {
    long epDay = toEpochDay();
    return getChronology().hashCode() ^ ((int) (epDay ^ (epDay >>> 32)));
  }

  @Override
  public String toString() {
    // getLong() reduces chances of exceptions in toString()
    long yoe = getLong(YEAR_OF_ERA);
    long moy = getLong(MONTH_OF_YEAR);
    long dom = getLong(DAY_OF_MONTH);
    StringBuilder buf = new StringBuilder(30);
    buf.append(getChronology().toString())
        .append(" ")
        .append(getEra())
        .append(" ")
        .append(yoe)
        .append(moy < 10 ? "-0" : "-").append(moy)
        .append(dom < 10 ? "-0" : "-").append(dom);
    return buf.toString();
  }

}
